文章目录
1 摘要
Spring Cloud Zookeeper 分布式服务注册中心搭建可参考:
33 Spring Boot 2.2 集成 Spring Cloud Zookeeper - 分布式服务注册中心 — 2020-02-23
本文将介绍 Spring Cloud Zookeeper 分布式服务消费者 - Ribbon
2 核心 Maven 依赖
./cloud-zookeeper-ribbon/pom.xml
<!-- Spring mvc -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- Spring cloud zookeeper -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zookeeper-all</artifactId>
<exclusions>
<exclusion>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Zookeeper -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>${zookeeper.version}</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency>
其中 ${zookeeper.version} 的版本为 3.4.12 (不要随意改版本号,会有兼容性问题)
注意: SpringBoot 的版本需要在 2.2及以上
3 配置文件
3.1 bootstrap.yml
./cloud-zookeeper-ribbon/src/main/resources/bootstrap.yml
## Application bootstrap config
## spring config
spring:
cloud:
zookeeper:
connect-string: 172.16.140.10:2181
3.2 application.yml
./cloud-zookeeper-ribbon/src/main/resources/application.yml
## Application config
## Server
server:
port: 8101
## Spring config
spring:
application:
name: cloud-zookeeper-ribbon
4 核心 Java 类
4.1 Service 层服务调用
./cloud-zookeeper-ribbon/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/ribbon/service/CloudZookeeperRibbonService.java
package com.ljq.demo.springboot.cloud.zookeeper.ribbon.service;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
import javax.annotation.Resource;
import java.util.Date;
/**
* @Description: Spring Cloud Zookeeper Ribbon 服务消费者业务层
* @Author: junqiang.lu
* @Date: 2020/2/24
*/
@Service("cloudZookeeperRibbonService")
public class CloudZookeeperRibbonService {
/**
* Zookeeper 服务注册中心服务名称
*/
private static final String CLOUD_ZOOKEEPER_PROVIDER_NAME = "cloud-zookeeper-provider";
/**
* Zookeeper 服务注册中心接口地址-打印用户名称
*/
private static final String API_PATH_ZOOKEEPER_HELLO = "/api/cloud/zookeeper/hello";
@Resource
private RestTemplate restTemplate;
/**
* 打印用户名称
*
* @param name
* @return
*/
public String sayHello(String name) {
StringBuilder reqUrl = new StringBuilder("http://");
reqUrl.append(CLOUD_ZOOKEEPER_PROVIDER_NAME);
reqUrl.append(API_PATH_ZOOKEEPER_HELLO);
reqUrl.append("?name=").append(name);
System.out.println(new Date() + "-" + reqUrl.toString());
return restTemplate.getForEntity(reqUrl.toString(), String.class).getBody();
}
}
使用 RestTemplate 来请求调用 Zookeeper 服务,这里 Ribbon 将服务名称(ServiceId) 来替代 ip + 端口(port),RestTemplate 默认是正常的 http 请求,这里需要对 RestTemplate 使用 Ribbon 提供的注解 @LoadBalanced ，具体使用见 SpringBoot 启动类 com.ljq.demo.springboot.cloud.zookeeper.ribbon.CloudZookeeperRibbonApplication
关于 Ribbon 的 @LoadBalanced 注解,其作用是实现客户端负载均衡，具体说明可参考:
由springcloud ribbon的 @LoadBalanced注解的使用理解
4.2 Controller 层
./cloud-zookeeper-ribbon/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/ribbon/controller/CloudZookeeperRibbonController.java
package com.ljq.demo.springboot.cloud.zookeeper.ribbon.controller;
import com.ljq.demo.springboot.cloud.zookeeper.ribbon.service.CloudZookeeperRibbonService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
/**
* @Description: Spring cloud Zookeeper Ribbon 服务消费者控制层
* @Author: junqiang.lu
* @Date: 2020/2/24
*/
@RestController
@RequestMapping("/api/cloud/zookeeper/ribbon")
public class CloudZookeeperRibbonController {
@Autowired
private CloudZookeeperRibbonService cloudZookeeperRibbonService;
/**
* 打印用户名称
*
* @param name
* @return
*/
@RequestMapping(value = "/sayHello", method = {RequestMethod.GET, RequestMethod.POST},
produces = {MediaType.APPLICATION_JSON_VALUE})
public String sayHello(@RequestParam("name") String name) {
return cloudZookeeperRibbonService.sayHello(name);
}
}
4.3 SpringBoot 启动类
./cloud-zookeeper-ribbon/src/main/java/com/ljq/demo/springboot/cloud/zookeeper/ribbon/CloudZookeeperRibbonApplication.java
package com.ljq.demo.springboot.cloud.zookeeper.ribbon;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
/**
* @author junqiang.lu
*/
@EnableDiscoveryClient
@SpringBootApplication
public class CloudZookeeperRibbonApplication {
public static void main(String[] args) {
SpringApplication.run(CloudZookeeperRibbonApplication.class, args);
}
@LoadBalanced
@Bean
RestTemplate restTemplate(){
return new RestTemplate();
}
}
@EnableDiscoveryClient 该注解可用于发现 Cloud 服务
@LoadBalanced 用于负载均衡,这里必须手动注入 RestTemplate,并使用 @LoadBalanced 注解，否则， RestTemplate 默认使用正常的 http 请求
5 测试
由于本次测试需要调用 Spring Cloud Zookeeper 服务，因此服务注册中心的项目(cloud-zookeeper-provider)必须先启动
接口请求:
GET http://127.0.0.1:8101/api/cloud/zookeeper/ribbon/sayHello?name=Are%20you%20%E6%AC%A7%E5%85%8B
返回结果:
Hello !Are you 欧克
server port : 8100
server timestamp: 1582599140197
从返回的结果中可以看出,返回的端口为服务注册中心项目( cloud-zoopeeper-provider)的http端口,使用 Ribbon 调用 Cloud Zoopeeper 服务成功
6 推荐参考资料
Zookeeper 完整系列教程 Spring-Cloud-Zookeeper-Based-Demo
由springcloud ribbon的 @LoadBalanced注解的使用理解
7 Github 源码
Gtihub 源码地址 : https://github.com/Flying9001/springBootDemo
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